• Notes:
    1. AY2017/2018 Semester 2, AY2018/2019 Semester 2, bidding data not available.
    2. The bidding statistics are highly non-normal, likely due to being bounded by zero (they cannot bid negative points or have negative bidders). May consider using zero-inflated or poisson regression if considering these statistics as dependent variables.

1 Phase 1: Setting Up Environment, Packages And Loading Data.

View Code/Details

1.3 >>Load myBid.RDS

1.5 >>Load myModInfo.RDS

2 Phase 2: Filter, Transform And Merge Data

View Code/Details

2.3 >>Transform And Merge

  • Transform
    • Created a new variable Level that denotes whether the module is Level 1, 2, 3 or 4.
    • Created a new variable BpQ that represents Bids per Quota, which is the number of bidders for each available quota of the module, derived from Bidders and Quota. Used as a measure of the popularity of a module, Higher BpQ signifies greater popularity.
    • Created a new variable LessonTime that denotes whether the lecture begins in the morning (before 12pm), in the afternoon (12pm to 4pm), in the evening (after 4pm).
  • Merge
    • Add the information from myModInfo to myBid.

3 Phase 3: Data Diagnostics

3.1 Univariate Descriptive Statistics

##    ModuleCode        AcadYear   Semester Round        Quota           Bidders        LowestBid       LowestSuccessfulBid   HighestBid                                        StudentAcctType     Level           BpQ             StartTime         DayText        LessonTime  
##  PL1101E: 324   2013/2014:493   1:1449   1A:634   Min.   :  1.00   Min.   :  0.0   Min.   :   0.00   Min.   :   0.0      Min.   :   0.0   New Students [P]                           : 314   Level 1: 324   Min.   : 0.00000   Min.   : 800   Monday   :479   Morning  : 723  
##  PL3232 : 124   2015/2016:485   2:1380   1B:389   1st Qu.:  4.00   1st Qu.:  1.0   1st Qu.:   1.00   1st Qu.:   1.0      1st Qu.:   1.0   NUS Students [G]                           : 141   Level 2: 169   1st Qu.: 0.02326   1st Qu.:1100   Tuesday  :588   Afternoon:1834  
##  PL3236 : 112   2014/2015:439            1C:273   Median : 15.00   Median :  3.0   Median :   1.00   Median :   1.0      Median : 400.0   NUS Students [P, G]                        : 327   Level 3:1520   Median : 0.33333   Median :1300   Wednesday:688   Evening  : 272  
##  PL3234 : 110   2016/2017:366            2A:410   Mean   : 25.95   Mean   : 13.2   Mean   :  70.16   Mean   : 258.7      Mean   : 732.7   NUS Students [P]                           : 331   Level 4: 816   Mean   : 1.05331   Mean   :1305   Thursday :684                   
##  PL3235 : 109   2012/2013:350            2B:463   3rd Qu.: 32.00   3rd Qu.: 10.0   3rd Qu.:   8.00   3rd Qu.: 271.0      3rd Qu.:1237.0   Returning Students [P]                     :1191                  3rd Qu.: 1.30000   3rd Qu.:1500   Friday   :390                   
##  PL3233 : 107   2011/2012:242            3A:366   Max.   :430.00   Max.   :440.0   Max.   :2430.00   Max.   :3459.0      Max.   :4801.0   Returning Students [P] and NUS Students [G]: 155                  Max.   :18.00000   Max.   :1900                                   
##  (Other):1943   (Other)  :454            3B:294                                                                                           Returning Students and New Students [P]    : 370

3.3.2 Continuous-Continuous

## Quota ~ Bidders

## Quota ~ LowestBid

## Quota ~ LowestSuccessfulBid

## Quota ~ HighestBid

## Quota ~ BpQ

## Quota ~ StartTime

## Bidders ~ LowestBid

## Bidders ~ LowestSuccessfulBid

## Bidders ~ HighestBid

## Bidders ~ BpQ

## Bidders ~ StartTime

## LowestBid ~ LowestSuccessfulBid

## LowestBid ~ HighestBid

## LowestBid ~ BpQ

## LowestBid ~ StartTime

## LowestSuccessfulBid ~ HighestBid

## LowestSuccessfulBid ~ BpQ

## LowestSuccessfulBid ~ StartTime

## HighestBid ~ BpQ

## HighestBid ~ StartTime

## BpQ ~ StartTime

View Continuous-Continuous Correlation Matrix

3.3.4 Continuous-Categorical

View Continuous-Categorical Boxplots

## AcadYear ~ Quota

## AcadYear ~ Bidders

## AcadYear ~ LowestBid

## AcadYear ~ LowestSuccessfulBid

## AcadYear ~ HighestBid

## AcadYear ~ BpQ

## AcadYear ~ StartTime

## Semester ~ Quota

## Semester ~ Bidders

## Semester ~ LowestBid

## Semester ~ LowestSuccessfulBid

## Semester ~ HighestBid

## Semester ~ BpQ

## Semester ~ StartTime

## Round ~ Quota

## Round ~ Bidders

## Round ~ LowestBid

## Round ~ LowestSuccessfulBid

## Round ~ HighestBid

## Round ~ BpQ

## Round ~ StartTime

## Level ~ Quota

## Level ~ Bidders

## Level ~ LowestBid

## Level ~ LowestSuccessfulBid

## Level ~ HighestBid

## Level ~ BpQ

## Level ~ StartTime

## DayText ~ Quota

## DayText ~ Bidders

## DayText ~ LowestBid

## DayText ~ LowestSuccessfulBid

## DayText ~ HighestBid

## DayText ~ BpQ

## DayText ~ StartTime

## LessonTime ~ Quota

## LessonTime ~ Bidders

## LessonTime ~ LowestBid

## LessonTime ~ LowestSuccessfulBid

## LessonTime ~ HighestBid

## LessonTime ~ BpQ

## LessonTime ~ StartTime

4 Phase 5: Exploration

# number of modules
unique(mydata$ModuleCode)
##  [1] PL1101E PL2131  PL2132  PL3232  PL3233  PL3234  PL3235  PL3236  PL3237  PL3238  PL3239  PL3240  PL3241  PL3242  PL3243  PL3244  PL3248  PL3249  PL3250  PL3251  PL3252  PL3253  PL3254  PL3255  PL3256  PL3257  PL3258  PL3259  PL3260  PL3261  PL3281  PL3281A PL3281B PL3281C PL3281D PL3282  PL3282A PL3282C PL3283  PL3283A PL3283B PL3284  PL3285  PL3286  PL3287  PL3288  PL3289  PL4201  PL4202  PL4203  PL4205  PL4206  PL4207  PL4208  PL4213  PL4214  PL4217  PL4218  PL4219  PL4220  PL4221  PL4222  PL4223  PL4224  PL4225  PL4226  PL4227  PL4228  PL4229  PL4230  PL4231  PL4232  PL4233  PL4234  PL4235  PL4237  PL4238  PL4239  PL4240  PL4241  PL4880F PL4880G PL4880H PL4880I PL4880J PL4880K PL4880L PL4880N PL4880P PL4880Q PL4880R
## Levels: PL1101E PL2131 PL2132 PL3232 PL3233 PL3234 PL3235 PL3236 PL3237 PL3238 PL3239 PL3240 PL3241 PL3242 PL3243 PL3244 PL3248 PL3249 PL3250 PL3251 PL3252 PL3253 PL3254 PL3255 PL3256 PL3257 PL3258 PL3259 PL3260 PL3261 PL3281 PL3281A PL3281B PL3281C PL3281D PL3282 PL3282A PL3282C PL3283 PL3283A PL3283B PL3284 PL3285 PL3286 PL3287 PL3288 PL3289 PL4201 PL4202 PL4203 PL4205 PL4206 PL4207 PL4208 PL4213 PL4214 PL4217 PL4218 PL4219 PL4220 PL4221 PL4222 PL4223 PL4224 PL4225 PL4226 PL4227 PL4228 PL4229 PL4230 PL4231 PL4232 PL4233 PL4234 PL4235 PL4237 PL4238 PL4239 PL4240 PL4241 PL4880F PL4880G PL4880H PL4880I PL4880J PL4880K PL4880L PL4880N PL4880P PL4880Q PL4880R
# number of rows belonging to each module
xtabs(~ ModuleCode, data  = mydata, subset = NULL)
## ModuleCode
## PL1101E  PL2131  PL2132  PL3232  PL3233  PL3234  PL3235  PL3236  PL3237  PL3238  PL3239  PL3240  PL3241  PL3242  PL3243  PL3244  PL3248  PL3249  PL3250  PL3251  PL3252  PL3253  PL3254  PL3255  PL3256  PL3257  PL3258  PL3259  PL3260  PL3261  PL3281 PL3281A PL3281B PL3281C PL3281D  PL3282 PL3282A PL3282C  PL3283 PL3283A PL3283B  PL3284  PL3285  PL3286  PL3287  PL3288  PL3289  PL4201  PL4202  PL4203  PL4205  PL4206  PL4207  PL4208  PL4213  PL4214  PL4217  PL4218  PL4219  PL4220  PL4221  PL4222  PL4223  PL4224  PL4225  PL4226  PL4227  PL4228  PL4229  PL4230  PL4231  PL4232  PL4233  PL4234  PL4235  PL4237  PL4238  PL4239  PL4240  PL4241 PL4880F PL4880G PL4880H PL4880I PL4880J PL4880K PL4880L PL4880N PL4880P PL4880Q PL4880R 
##     324      84      85     124     107     110     109     112      49      35      41      37      50      46      14      29      24      21      27      16      29       3      36      21      17      17      21      15       4      50      45      44      10      11      40      39      13       6       2       6      22      37       6      30      22      22       1      23      37      43      36      43      19      13      22      20      13      26      24       5      39      30      13      20       2      18      24      16      20       7      17       5       3      22      40      43      11       2       4       5      15      15       6       6      18      15      33       4       7       4      28
# datatable(myBid, filter = "top")
aggregate(BpQ ~ AcadYear + Semester + ModuleCode,
          data = mydata,
          FUN = mean)